In recent years, network functions are deployed on a general-purpose computer with the use of virtualization technology. This is called network functions virtualization (NFV). In the NFV, network functions that are conventionally carried out by firewalls, load balancers, and the like are virtualized. Virtual machines that virtualize network functions are referred to as virtualized network functions (VNFs). In the case where a physical node with a plurality of VNFs is connected to a wide area network (WAN), each of the VNFs implements communication via the WAN. A WAN is a network that exists, for example, across a plurality of countries and is supported by a plurality of communication carriers. Such a WAN includes wired and wireless networks.
In the case where each VNF implements communication via a WAN, knowing the bandwidth of the communication channel enhances communication efficiency. For example, VNFs transmit data at a communication speed according to bottleneck bandwidth of the communication channel to thereby achieve communication with the efficient use of available bandwidth. In view of this, each VNF performs available bandwidth measuring in order to increase transmission efficiency of the communication via the WAN. The available bandwidth of the communication via the WAN is the least remaining communication capacity across the communication channel via the WAN. The remaining communication capacity across the communication channel is a difference between the maximum communication speed of, for example, a link connecting devices and the actual communication speed of data currently transferred on the link. In the available bandwidth measuring, communication is repeated with changing, for example, the data transmission speed (transmission rate). Then, the maximum transmission rate enabling data reception at a speed comparable to the transmission rate is determined as the available bandwidth.
As for useful technology for understanding the state of a virtual network, there is provided, for example, a network state estimation apparatus capable of gaining an accurate understanding of the network states of individual virtual networks even over which a network control function is exercised to limit resources available to each of the virtual networks. There is also provided a bandwidth measuring method for a packet communication network, to reduce load on the communication network due to bandwidth measuring by eliminating unwanted bandwidth measuring operations. Further, there is provided a bandwidth control apparatus capable of improving bandwidth use efficiency by controlling bandwidths according to actual usage status while reducing computer resources needed for monitoring communication sessions.
Japanese Laid-open Patent Publication No. 2013-074494
Japanese Laid-open Patent Publication No. 2008-131100
International Publication Pamphlet No. WO 2015162753
In the case where, on one single physical node, a plurality of VNFs that communicate with a different particular physical node are deployed, if the VNFs individually make available bandwidth measuring, the VNFs are not able to share information of each other's measuring results, which therefore leads to creating extra communication load.